This invention relates to a piston accumulator having a piston-poppet assembly to equalize substantially the liquid-gas pressure appearing across the piston seal. Such as arrangement greatly reduces gas charge leakage into the hydraulic chamber of the accumulator.
Most piston accumulators incorporate two seals on the piston. One seal contains the liquid and the other seal contains the gas, with a space between the two seals. Other piston accumulators employ only one piston seal to separate the liquid and gas directly.
With either sealing arrangement, a possible leakage problem occurs when there is pressure exerted only on one side of a seal. The problem is particularly aggravated if pressure exists only on the gas side of the piston. With this condition, the gas will eventually bypass the seal and flow into the hydraulic side when the hydraulic pressure is at a low value or zero. The efficiency of the accumulator is thus reduced, and the accumulator operation impaired.